2009-10-27

Until now, scientists have attempted to develop spin transistors by incorporating local ferromagnets into device architectures. This results in significant design complexities, especially in view of the rising demand for smaller and smaller transistors," says Philippe Debray, research professor in the Department of Physics in the McMicken College of Arts & Sciences. "A far better and practical way to manipulate the orientation of an electron's spin would be by using purely electrical means, like the switching on and off of an electrical voltage. This will be spintronics without ferromagnetism or all-electric spintronics, the holy grail of semiconductor spintronics."

2009-10-24

What I didn’t appreciate, until I finally unzipped and untarred a copy of ftp://elsie.nci.nih.gov/pub/tzdata2009o.tar.gz, is the historical scholarship scribbled in the margins of this remarkable database, or document, or hybrid of the two.

2009-10-23

A team of engineers from the University of Pennsylvania has transformed simple nanowires into reconfigurable materials and circuits, demonstrating a novel, self-assembling method for chemically creating nanoscale structures that are not possible to grow or obtain otherwise.

A team of Harvard chemists led by X. Sunney Xie has developed a new microscopic technique for seeing, in color, molecules with undetectable fluorescence. The room-temperature technique allows researchers to identify previously unseen molecules in living organisms and offers broad applications in biomedical imaging and research.

A tiny ladderlike beam of silicon converts light into vibrations and vice versa with extremely high efficiency, physicists report. That may seem like an esoteric result, but the finding could open the way to new physics and someday serve as a key element in optical microcircuits akin to the electronic microcircuits in computer chips.

2009-10-22

If the promise of nanotechnology is to be fulfilled, nanoparticles will have to be able to make something of themselves. An important advance towards this goal has been achieved by researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory who have found a simple and yet powerfully robust way to induce nanoparticles to assemble themselves into complex arrays.

Very little mechanical energy would be needed to power the new nanogenerator because even a small amount of displacement has a larger effect on nanoscale materials than regular materials — a theory Wang intends to prove in his lab.

Researchers at the University of California, Riverside have created in the laboratory a class of carbenes, highly reactive molecules, used to make catalysts - substances that facilitate chemical reactions. Until now, chemists believed these carbenes, called "abnormal N-heterocyclic carbenes" or aNHCs, were impossible to make.

2009-10-19

"If you open up almost any electronic gadget, you will see various elements that operating using electric circuitries," Nader Engheta tells PhysOrg.com. "Many of them have different functionalities, such as inductors, capacitors, resistors, transistors, and so forth. These well-known elements have been around for decades. But what if you could bring these concepts to the nanoscale, and what if they could operate with light instead of electricity?"

2009-10-16

A team of European researchers has demonstrated some of the first commercially viable plasmonic devices, paving the way for a new era of high-speed communications and computing in which electronic and optical signals can be handled simultaneously.

In the past 5 years, no material has excited more interest from condensed matter physicists than graphene, a sheet of carbon only one atom thick. Electrons zing through the stuff in an unusual way, and they flow so easily that graphene could someday replace silicon and other semiconductors as the material of choice for microchips. Now, a team of physicists has taken a key step in fulfilling graphene's promise as a hotbed of exotic physics by showing that the electrons within it can team up to behave like particles with a fraction of the electron's charge.

2009-10-15

A new kind of portable electrochemical battery that can produce thousands of hours of power - and soon replace the expensive regular or rechargeable batteries in hearing aids and sensors and eventually in cellphones, laptop computers and even electric cars - has been developed at Haifa's Technion-Israel Institute of Technology.

Kris Gevaert from VIB/Ghent University (Belgium) and colleagues from the universities of Freiburg and Bochum have achieved a breakthrough in protein research. Using yeast, they have succeeded in making virtually the complete inventory of all the proteins in the mitochondria, the energy producers found in every cell. Their research findings are being published in Cell.

2009-10-14

Although the human genome sequence faithfully lists (almost) every single DNA base of the roughly 3 billion bases that make up a human genome, it doesn't tell biologists much about how its function is regulated. Now, researchers at the Salk Institute provide the first detailed map of the human epigenome, the layer of genetic control beyond the regulation inherent in the sequence of the genes themselves.

"Thanks to the Human Genome Project, biology and medicine today may be at a point similar to where physics was after the advent of the telescope," said Orly Alter, assistant professor of biomedical engineering at the university. "The rapidly growing number of large-scale DNA microarray data sets hold the key to the discovery of cellular mechanisms, just as the astronomical tables compiled by Galileo and Tycho after the invention of the telescope enabled accurate predictions of planetary motions and, later, the discovery of universal gravitation. And just as Kepler and Newton made these predictions and discoveries by using mathematical frameworks to describe trends in astronomical data, so future discovery and control in biology and medicine will come from the mathematical modeling of large-scale molecular biological data."

2009-10-13

The project's results raise the prospect of building single molecule diodes - the smallest devices one can ever build. "I think it's exciting because we are able to look at a single molecule and play with it, " Tao says. "We can apply a voltage, a mechanical force, or optical field, measure current and see the response. As quantum physics controls the behaviors of single molecules, this capability allows us to study properties distinct from those of conventional devices."

2009-10-09

In recent years, quantum computers have lost some of their luster. In the 1990s, it seemed that they might be able to solve a class of difficult but common problems — the so-called NP-complete problems — exponentially faster than classical computers. Now, it seems that they probably can't. In fact, until this week, the only common calculation where quantum computation promised exponential gains was the factoring of large numbers, which isn't that useful outside cryptography.

2009-10-07

Japanese researchers working with R. Kitaura and H. Shinohara have now developed a new method that is simple and delivers stable nanowires: They deposit metal atoms inside of carbon nanotubes. As the scientists report in the journal Angewandte Chemie, this forms metal wires of individual atoms lined up side-by-side that are so well protected by their sheath that they have long-term stability.

Until now, no one has produced experimental evidence that chaos occurs in the quantum world, the world of photons, atoms, molecules and their building blocks....Now, however, Jessen and his group in UA's College of Optical Sciences have performed a series of experiments that show just how classical chaos spills over into the quantum world.

For the first time, physicists have demonstrated the quantum entanglement of three light beams, all of different wavelengths. Entanglement of two light beams of different wavelengths has already been demonstrated, but the researchers explain that going beyond two beams is important since three beams can serve as connections at the nodes of a quantum network.

2009-10-06

An international team of astronomers have found an unexpected link between mysterious 'dark matter' and the visible stars and gas in galaxies that could revolutionise our current understanding of gravity.

2009-10-05

European researchers have created a CMOS (semiconductor) camera capable of filming individual photons one million times a second. The breakthrough will impact on all the most advanced areas of science and makes Europe the world leader in the technology.